KOS , Greece (AFP) - Greece on Friday sent a ship to the resort island of Kos to speed up the registration of hundreds of Syrian refugees following mounting tensions over a huge influx of new arrivals.

The Eleftherios Venizelos docked in Kos in the afternoon and will be moored for about two weeks during which authorities will register newcomers to the island, said Major-General Zakharoula Tsirigoti, the head of the Greek police's immigration department.

But the Syrians, most of whom are living rough - either sleeping in tents or on the beach - will not be hosted on the ship.

"It's only for the screening and briefing of the Syrians," Tsirigoti told reporters.

She said she expected registration on the boat to start "hopefully tomorrow, or if we manage to prepare everything, tonight."

The ship will not be used to register any Iraqis, Afghans or any of the other new arrivals on the island, who Tsigiroti said were "immigrants, not refugees".

Earlier this week, about 2,000 refugees and immigrants were relocated to a football stadium.

Overwhelmed police beat them with truncheons and sprayed fire extinguishers during a scuffle on Tuesday.

'LONG-TERM SOLUTION NEEDED'

At the start of the week, there were about 7,000 migrants and refugees on the island, which is home to some 30,000 people.

According to the officer, some 2,500 refugees and migrants now remain, with many taking regular ferry services to Athens once they are registered.

"Tonight, we are expecting some 1,900 Syrians to leave the island," Tsirigoti said.

From Athens, most of the migrants and refugees hope to leave Greece for countries further north, including Germany and Sweden.

Medical charity Doctors Without Borders (MSF) criticised the government's initiative to register the Syrians on the ship.

"What we want is a long-term solution, which is reception," said MSF's humanitarian affairs officer Constance Theisen.

"If this boat is only temporary, it's ridiculous," she told AFP.

Kos Mayor George Kiritsis said Greece cannot deal with the crisis alone, however.

"The European Union has to help financially (with) the immigration problem," Kiristis told reporters at the port.

"Also the European Union must understand that at some point, the countries have to share the people that are coming here, or else the problem won't be solved. The people are still going to be coming here to find a better place," he added.

Some 124,000 refugees and migrants landed on the Greek islands during the first seven months of the year - up 750 per cent from 2014, according to UN figures.